Space isn't a complete vacuum—there’s weather out there, too. The Sun is always emitting charged particles, known as solar wind, as well as the occasional coronal mass ejection, a bubble of gas and magnetic field. When these charged particles interact with the Earth’s atmosphere, they create the Northern Lights, but they also make their way much farther across the solar system.
This simulation from NASA shows how space weather makes its way all the way to Pluto. The charged particles travel for months, threading together to become larger clouds of particles and magnetic field. According to WIRED, "Red represents temperature (the brighter it is, the hotter), green means density, and the blue areas are strong shock waves moving through the plasma. ... Those tinges of purple ... are low-density hot shocks."
Knowing exactly how space weather moves can help NASA prepare its spacecraft for traveling through radiation.
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